Mike,
Try reducing the HV setting in ISODAT to 2.2kV prior to pushing the 'Source'
button on the source controller. Once the HV and Emission LED's come on I
then retore the HV setting in ISODAT to 3.0kV. Set the HV value by
right-clicking in the HV software window of ISODAT (upper left corner of the
window).
Mark
_____
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Kubo, Michael D. (ARC-SSX)[SETI INSTITUTE]
Sent: Wednesday, July 29, 2009 1:23 PM
To: [log in to unmask]
Subject: [ISOGEOCHEM] Source HV Down on a ThermoFinnigan Delta Plus XL
Hello Everyone,
Of course, just before I'm about to run a 1 shot meteorite sample, our HV
just went down. Here is the play by play:
1) Had been running EA, so before I opened the GC-C-III SGE valve, I
turned off the filament HV button the front panel so as not to flood the
source with gas and trip the HV.
2) Came back around to the front side of the instrument panel to turn
the source HV back on. Depressed button, only to see that neither the
source HV light or the emission light came on, but the red LED on the button
did. In addition, the source HV light on the pump LED panel was also off.
Source vacuum indicates 3.3 X 10^-5 - clearly not the vacuum of 10^-6/10^-7
I typically operate at.
3) If I try power cycling the "pump" switch on the front of the
instrument, the pump source HV LED will flash twice, then stay out.
So my guess is that I have a bad source turbo and the source HV won't kick
on because of this. If anyone out there has other ideas that don't involve
weeks of downtime and several (tens of) thousands of dollars to repair,
PLEASE shoot me an email! Your help is greatly appreciated (as always) and
a lonely chunk of meteorite will be very grateful as well.
Cheers,
Mike Kubo
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************************************************************
Michael D. Kubo
NASA Ames Research Center
M/S 239-4
Bldg. N239, Room 327
Moffett Field, CA 94035
(650) 604-6110
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